Reader for chip cards

ABSTRACT

Read apparatus for chip cards with a housing (1) in which a contact support (3), with a number of contact pairs (4,4a) that corresponds to the number of read tracks and that can be connected by a limit switch (12), is held and a slide (6), operated by the chip card and acting on the contacts (4,4a) or the contact support (3), is guided such that, upon moving the card close to its end position, the contacts (4,4a) are pressed, on the one hand, firmly onto the contact field of the chip by means of the slide (6) and, on the other hand, the limit switch (12) is closed, wherein the limit switch (12) is arranged on the side next to the contact support (3) in the area between the card insertion slot and the slide (6), and wherein the slide (6) is equipped with a bar (13) having a tab (14) which reaches behind the contacts (12a, 12b) of the limit switch on the side of the card insertion slot with a spacing such that the limit switch (12) is closed by the entrainment of the slide (6) brought about by the approach of the card to its end position.

BACKGROUND OF THE INVENTION

The invention proceeds from a read apparatus for chip cards according tothe preamble of claim 1. In known read apparatuses of this type, thelimit switch closing the circuit between the contacts and the readtracks is in the vicinity of the contact support, as a rule, directly ontop of the contact support, such that, upon insertion into the cardslot, the chip card entrains one of the contacts and presses it againstthe opposing contact immediately before reaching its final position.Functionally, the arrangement has largely proven itself, but nonethelessthe position of the limit switch in the end area of the chip card isconsidered disadvantageous in that, in case of frequent actuation, thatis, frequent insertion end pulling out of the card, the appearance ofworn-off material from the card is inevitable, accumulating inparticular on the opposing contact and leading to an insulation effectall the way to complete interruption of functioning.

The present invention is based on the problem of creating a readapparatus for chip cards in which the contamination of the contact byworn-off material or by the card in some other manner is largelyavoided.

SUMMARY OF THE INVENTION

This problem is solved by a read apparatus with the characteristicsreproduced in claim.

A read apparatus for chip cards is created by the invention in which thelimit switch lies inside a closed chamber which is largely hermeticallyenclosed and thus is practically completely protected against theingress of dust. Differing from the known limit switch arrangements,moreover, a pivoting of the two contact blades takes place during theentrainment after landing of the entrained contact on the opposingcontact, due to the play that must be maintained, and thus, because oftheir differing pivot radii, a displacement of the contact point takesplace with a frictional effect, whereby a continual self-cleaning of thecontact field is brought about.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

Further details of the invention characterized in the claims areexplained below on the basis of the attached drawings. These show, in

FIG. 1, a view from above onto the housing of the read apparatus;

FIG. 2, a view from below onto the read apparatus reproduced in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The read apparatus for chip card consists of a housing 1 that is closedoff by means of a lid, not shown, and into which the chip card is pushedfor operation under lateral guidance by means of the leaf springs 2 inthe direction designated by the arrow. Inside the housing, a contactsupport 3, with a number of contact pairs 4,4a corresponding to thenumber of contacting fields, is held. Also provided is a slide 6 runningon guides 5, which in the case of this example is pressed upon by aspring 7 in the direction towards the insertion slot and has a stop 8,against which the chip card makes contact with its front end whenapproaching its final (read) position. Inclined ramps 9 are alsoarranged on the slide and interact with pins 10 arranged on the contactsupport 3 such that, upon approach of the card to its final position,the slide 6 is entrained and in the process the inclined ramps 9 slidingup onto the pins 10 of the contact support 3 bring about a pivoting ofthe contact support 3 and thus the contact pairs 4, 4a, such that theyare pressed firmly onto the chip arranged on the card.

The limit switch 12 is arranged on the side next to the contact support3 in the area between the card insertion slot and the slide 6, the slide6 being equipped by means of a bar 13 (FIG. 1) with a tab 14 (FIG. 2)which, upon displacement of the slide 6 under the force of the insertedcard first strikes the contact 12a and then entrains it on itsadditional travel to contact 12b, whereby the electrically conductiveconnection is produced. It can be recognized from the drawing that theswitch lies in a chamber which is formed by the housing 1 and thehousing lid, not shown, and is largely hermetically enclosed and thuspractically completely protected against the ingress of dust. It is alsoclearly recognizable that the two contracts 12a, 12b, because of thediffering positions of their pivot circles after the placement of thecontact 12a on the contact 12b, slide against one another a with africtional displacement of the contact point, whereby a continualself-cleaning of the contact field of the switch is brought about.

What is claimed is:
 1. Read apparatus for chip cards with a housing (1)in which a contact support (3), with a number of contact pairs (4,4a)that corresponds to the number of read tracks and that can be connectedby a limit switch (12), is held and a slide (6) operated by the chipcard and acting on the contacts (4, 4a) or the contact support (3) isguided such that upon moving the card close to its end position, thecontacts (4,4a) are pressed, on the one hand, firmly onto the contactfield of the chip by means of the slide (6) and, on the other hand, thelimit switch (12) is arranged on the side next to the contact support(3) in the area between the card insertion slot and the slide (6), andin that the slide (6) is equipped with a tab (13,14) which reachesbehind the contacts (12a, 12b) of the limit switch on the side of thecard insertion slot with a spacing such that the limit switch (12) isclosed by the entrainment of the slide (6) brought about by the approachof the card to its end position.
 2. Read apparatus for chip cardsaccording to claim 1, characterized in that the limit switch (12) isformed by two small leaf springs (12a, 12b) held so as to pivot.